I started with the cheap stuff and always had an issue with what appeared to be the transmission stalling. This is a known issue that you can read about at this site. When I changed to the high octane, one time just to try it, the problem went away and I had completely smooth accelleration. I also get better milage, and with the prices today it only costs about 20 cents more a gallon which is about 5% more for 6%, as someone stated, better milage.